|
- /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
- * All rights reserved.
- *
- * This package is an SSL implementation written
- * by Eric Young (eay@cryptsoft.com).
- * The implementation was written so as to conform with Netscapes SSL.
- *
- * This library is free for commercial and non-commercial use as long as
- * the following conditions are aheared to. The following conditions
- * apply to all code found in this distribution, be it the RC4, RSA,
- * lhash, DES, etc., code; not just the SSL code. The SSL documentation
- * included with this distribution is covered by the same copyright terms
- * except that the holder is Tim Hudson (tjh@cryptsoft.com).
- *
- * Copyright remains Eric Young's, and as such any Copyright notices in
- * the code are not to be removed.
- * If this package is used in a product, Eric Young should be given attribution
- * as the author of the parts of the library used.
- * This can be in the form of a textual message at program startup or
- * in documentation (online or textual) provided with the package.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * "This product includes cryptographic software written by
- * Eric Young (eay@cryptsoft.com)"
- * The word 'cryptographic' can be left out if the rouines from the library
- * being used are not cryptographic related :-).
- * 4. If you include any Windows specific code (or a derivative thereof) from
- * the apps directory (application code) you must include an acknowledgement:
- * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
- *
- * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- * The licence and distribution terms for any publically available version or
- * derivative of this code cannot be changed. i.e. this code cannot simply be
- * copied and put under another distribution licence
- * [including the GNU Public Licence.] */
-
- #include <openssl/rsa.h>
-
- #include <string.h>
-
- #include <openssl/bn.h>
- #include <openssl/engine.h>
- #include <openssl/err.h>
- #include <openssl/ex_data.h>
- #include <openssl/mem.h>
- #include <openssl/obj.h>
- #include <openssl/thread.h>
-
- #include "internal.h"
- #include "../internal.h"
-
-
- extern const RSA_METHOD RSA_default_method;
-
- static CRYPTO_EX_DATA_CLASS g_ex_data_class = CRYPTO_EX_DATA_CLASS_INIT;
-
- RSA *RSA_new(void) { return RSA_new_method(NULL); }
-
- RSA *RSA_new_method(const ENGINE *engine) {
- RSA *rsa = (RSA *)OPENSSL_malloc(sizeof(RSA));
- if (rsa == NULL) {
- OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
- return NULL;
- }
-
- memset(rsa, 0, sizeof(RSA));
-
- if (engine) {
- rsa->meth = ENGINE_get_RSA_method(engine);
- }
-
- if (rsa->meth == NULL) {
- rsa->meth = (RSA_METHOD*) &RSA_default_method;
- }
- METHOD_ref(rsa->meth);
-
- rsa->references = 1;
- rsa->flags = rsa->meth->flags;
- CRYPTO_MUTEX_init(&rsa->lock);
-
- if (!CRYPTO_new_ex_data(&g_ex_data_class, rsa, &rsa->ex_data)) {
- METHOD_unref(rsa->meth);
- OPENSSL_free(rsa);
- return NULL;
- }
-
- if (rsa->meth->init && !rsa->meth->init(rsa)) {
- CRYPTO_free_ex_data(&g_ex_data_class, rsa, &rsa->ex_data);
- METHOD_unref(rsa->meth);
- OPENSSL_free(rsa);
- return NULL;
- }
-
- return rsa;
- }
-
- void RSA_additional_prime_free(RSA_additional_prime *ap) {
- if (ap == NULL) {
- return;
- }
-
- BN_clear_free(ap->prime);
- BN_clear_free(ap->exp);
- BN_clear_free(ap->coeff);
- BN_clear_free(ap->r);
- OPENSSL_free(ap);
- }
-
- void RSA_free(RSA *rsa) {
- unsigned u;
-
- if (rsa == NULL) {
- return;
- }
-
- if (!CRYPTO_refcount_dec_and_test_zero(&rsa->references)) {
- return;
- }
-
- if (rsa->meth->finish) {
- rsa->meth->finish(rsa);
- }
- METHOD_unref(rsa->meth);
-
- CRYPTO_free_ex_data(&g_ex_data_class, rsa, &rsa->ex_data);
-
- BN_clear_free(rsa->n);
- BN_clear_free(rsa->e);
- BN_clear_free(rsa->d);
- BN_clear_free(rsa->p);
- BN_clear_free(rsa->q);
- BN_clear_free(rsa->dmp1);
- BN_clear_free(rsa->dmq1);
- BN_clear_free(rsa->iqmp);
- for (u = 0; u < rsa->num_blindings; u++) {
- BN_BLINDING_free(rsa->blindings[u]);
- }
- OPENSSL_free(rsa->blindings);
- OPENSSL_free(rsa->blindings_inuse);
- if (rsa->additional_primes != NULL) {
- sk_RSA_additional_prime_pop_free(rsa->additional_primes,
- RSA_additional_prime_free);
- }
- CRYPTO_MUTEX_cleanup(&rsa->lock);
- OPENSSL_free(rsa);
- }
-
- int RSA_up_ref(RSA *rsa) {
- CRYPTO_refcount_inc(&rsa->references);
- return 1;
- }
-
- int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb) {
- if (rsa->meth->keygen) {
- return rsa->meth->keygen(rsa, bits, e_value, cb);
- }
-
- return RSA_default_method.keygen(rsa, bits, e_value, cb);
- }
-
- int RSA_generate_multi_prime_key(RSA *rsa, int bits, int num_primes,
- BIGNUM *e_value, BN_GENCB *cb) {
- if (rsa->meth->multi_prime_keygen) {
- return rsa->meth->multi_prime_keygen(rsa, bits, num_primes, e_value, cb);
- }
-
- return RSA_default_method.multi_prime_keygen(rsa, bits, num_primes, e_value,
- cb);
- }
-
- int RSA_encrypt(RSA *rsa, size_t *out_len, uint8_t *out, size_t max_out,
- const uint8_t *in, size_t in_len, int padding) {
- if (rsa->meth->encrypt) {
- return rsa->meth->encrypt(rsa, out_len, out, max_out, in, in_len, padding);
- }
-
- return RSA_default_method.encrypt(rsa, out_len, out, max_out, in, in_len,
- padding);
- }
-
- int RSA_public_encrypt(int flen, const uint8_t *from, uint8_t *to, RSA *rsa,
- int padding) {
- size_t out_len;
-
- if (!RSA_encrypt(rsa, &out_len, to, RSA_size(rsa), from, flen, padding)) {
- return -1;
- }
-
- return out_len;
- }
-
- int RSA_sign_raw(RSA *rsa, size_t *out_len, uint8_t *out, size_t max_out,
- const uint8_t *in, size_t in_len, int padding) {
- if (rsa->meth->sign_raw) {
- return rsa->meth->sign_raw(rsa, out_len, out, max_out, in, in_len, padding);
- }
-
- return RSA_default_method.sign_raw(rsa, out_len, out, max_out, in, in_len,
- padding);
- }
-
- int RSA_private_encrypt(int flen, const uint8_t *from, uint8_t *to, RSA *rsa,
- int padding) {
- size_t out_len;
-
- if (!RSA_sign_raw(rsa, &out_len, to, RSA_size(rsa), from, flen, padding)) {
- return -1;
- }
-
- return out_len;
- }
-
- int RSA_decrypt(RSA *rsa, size_t *out_len, uint8_t *out, size_t max_out,
- const uint8_t *in, size_t in_len, int padding) {
- if (rsa->meth->decrypt) {
- return rsa->meth->decrypt(rsa, out_len, out, max_out, in, in_len, padding);
- }
-
- return RSA_default_method.decrypt(rsa, out_len, out, max_out, in, in_len,
- padding);
- }
-
- int RSA_private_decrypt(int flen, const uint8_t *from, uint8_t *to, RSA *rsa,
- int padding) {
- size_t out_len;
-
- if (!RSA_decrypt(rsa, &out_len, to, RSA_size(rsa), from, flen, padding)) {
- return -1;
- }
-
- return out_len;
- }
-
- int RSA_verify_raw(RSA *rsa, size_t *out_len, uint8_t *out, size_t max_out,
- const uint8_t *in, size_t in_len, int padding) {
- if (rsa->meth->verify_raw) {
- return rsa->meth->verify_raw(rsa, out_len, out, max_out, in, in_len, padding);
- }
-
- return RSA_default_method.verify_raw(rsa, out_len, out, max_out, in, in_len,
- padding);
- }
-
- int RSA_public_decrypt(int flen, const uint8_t *from, uint8_t *to, RSA *rsa,
- int padding) {
- size_t out_len;
-
- if (!RSA_verify_raw(rsa, &out_len, to, RSA_size(rsa), from, flen, padding)) {
- return -1;
- }
-
- return out_len;
- }
-
- unsigned RSA_size(const RSA *rsa) {
- if (rsa->meth->size) {
- return rsa->meth->size(rsa);
- }
-
- return RSA_default_method.size(rsa);
- }
-
- int RSA_is_opaque(const RSA *rsa) {
- return rsa->meth && (rsa->meth->flags & RSA_FLAG_OPAQUE);
- }
-
- int RSA_supports_digest(const RSA *rsa, const EVP_MD *md) {
- if (rsa->meth && rsa->meth->supports_digest) {
- return rsa->meth->supports_digest(rsa, md);
- }
- return 1;
- }
-
- int RSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
- CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func) {
- int index;
- if (!CRYPTO_get_ex_new_index(&g_ex_data_class, &index, argl, argp, new_func,
- dup_func, free_func)) {
- return -1;
- }
- return index;
- }
-
- int RSA_set_ex_data(RSA *d, int idx, void *arg) {
- return CRYPTO_set_ex_data(&d->ex_data, idx, arg);
- }
-
- void *RSA_get_ex_data(const RSA *d, int idx) {
- return CRYPTO_get_ex_data(&d->ex_data, idx);
- }
-
- /* SSL_SIG_LENGTH is the size of an SSL/TLS (prior to TLS 1.2) signature: it's
- * the length of an MD5 and SHA1 hash. */
- static const unsigned SSL_SIG_LENGTH = 36;
-
- /* pkcs1_sig_prefix contains the ASN.1, DER encoded prefix for a hash that is
- * to be signed with PKCS#1. */
- struct pkcs1_sig_prefix {
- /* nid identifies the hash function. */
- int nid;
- /* len is the number of bytes of |bytes| which are valid. */
- uint8_t len;
- /* bytes contains the DER bytes. */
- uint8_t bytes[19];
- };
-
- /* kPKCS1SigPrefixes contains the ASN.1 prefixes for PKCS#1 signatures with
- * different hash functions. */
- static const struct pkcs1_sig_prefix kPKCS1SigPrefixes[] = {
- {
- NID_md5,
- 18,
- {0x30, 0x20, 0x30, 0x0c, 0x06, 0x08, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d,
- 0x02, 0x05, 0x05, 0x00, 0x04, 0x10},
- },
- {
- NID_sha1,
- 15,
- {0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x0e, 0x03, 0x02, 0x1a, 0x05,
- 0x00, 0x04, 0x14},
- },
- {
- NID_sha224,
- 19,
- {0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
- 0x04, 0x02, 0x04, 0x05, 0x00, 0x04, 0x1c},
- },
- {
- NID_sha256,
- 19,
- {0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
- 0x04, 0x02, 0x01, 0x05, 0x00, 0x04, 0x20},
- },
- {
- NID_sha384,
- 19,
- {0x30, 0x41, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
- 0x04, 0x02, 0x02, 0x05, 0x00, 0x04, 0x30},
- },
- {
- NID_sha512,
- 19,
- {0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
- 0x04, 0x02, 0x03, 0x05, 0x00, 0x04, 0x40},
- },
- {
- NID_undef, 0, {0},
- },
- };
-
- int RSA_add_pkcs1_prefix(uint8_t **out_msg, size_t *out_msg_len,
- int *is_alloced, int hash_nid, const uint8_t *msg,
- size_t msg_len) {
- unsigned i;
-
- if (hash_nid == NID_md5_sha1) {
- /* Special case: SSL signature, just check the length. */
- if (msg_len != SSL_SIG_LENGTH) {
- OPENSSL_PUT_ERROR(RSA, RSA_R_INVALID_MESSAGE_LENGTH);
- return 0;
- }
-
- *out_msg = (uint8_t*) msg;
- *out_msg_len = SSL_SIG_LENGTH;
- *is_alloced = 0;
- return 1;
- }
-
- for (i = 0; kPKCS1SigPrefixes[i].nid != NID_undef; i++) {
- const struct pkcs1_sig_prefix *sig_prefix = &kPKCS1SigPrefixes[i];
- if (sig_prefix->nid != hash_nid) {
- continue;
- }
-
- const uint8_t* prefix = sig_prefix->bytes;
- unsigned prefix_len = sig_prefix->len;
- unsigned signed_msg_len;
- uint8_t *signed_msg;
-
- signed_msg_len = prefix_len + msg_len;
- if (signed_msg_len < prefix_len) {
- OPENSSL_PUT_ERROR(RSA, RSA_R_TOO_LONG);
- return 0;
- }
-
- signed_msg = OPENSSL_malloc(signed_msg_len);
- if (!signed_msg) {
- OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
- return 0;
- }
-
- memcpy(signed_msg, prefix, prefix_len);
- memcpy(signed_msg + prefix_len, msg, msg_len);
-
- *out_msg = signed_msg;
- *out_msg_len = signed_msg_len;
- *is_alloced = 1;
-
- return 1;
- }
-
- OPENSSL_PUT_ERROR(RSA, RSA_R_UNKNOWN_ALGORITHM_TYPE);
- return 0;
- }
-
- int RSA_sign(int hash_nid, const uint8_t *in, unsigned in_len, uint8_t *out,
- unsigned *out_len, RSA *rsa) {
- const unsigned rsa_size = RSA_size(rsa);
- int ret = 0;
- uint8_t *signed_msg;
- size_t signed_msg_len;
- int signed_msg_is_alloced = 0;
- size_t size_t_out_len;
-
- if (rsa->meth->sign) {
- return rsa->meth->sign(hash_nid, in, in_len, out, out_len, rsa);
- }
-
- if (!RSA_add_pkcs1_prefix(&signed_msg, &signed_msg_len,
- &signed_msg_is_alloced, hash_nid, in, in_len)) {
- return 0;
- }
-
- if (rsa_size < RSA_PKCS1_PADDING_SIZE ||
- signed_msg_len > rsa_size - RSA_PKCS1_PADDING_SIZE) {
- OPENSSL_PUT_ERROR(RSA, RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
- goto finish;
- }
-
- if (RSA_sign_raw(rsa, &size_t_out_len, out, rsa_size, signed_msg,
- signed_msg_len, RSA_PKCS1_PADDING)) {
- *out_len = size_t_out_len;
- ret = 1;
- }
-
- finish:
- if (signed_msg_is_alloced) {
- OPENSSL_free(signed_msg);
- }
- return ret;
- }
-
- int RSA_verify(int hash_nid, const uint8_t *msg, size_t msg_len,
- const uint8_t *sig, size_t sig_len, RSA *rsa) {
- const size_t rsa_size = RSA_size(rsa);
- uint8_t *buf = NULL;
- int ret = 0;
- uint8_t *signed_msg = NULL;
- size_t signed_msg_len, len;
- int signed_msg_is_alloced = 0;
-
- if (rsa->meth->verify) {
- return rsa->meth->verify(hash_nid, msg, msg_len, sig, sig_len, rsa);
- }
-
- if (sig_len != rsa_size) {
- OPENSSL_PUT_ERROR(RSA, RSA_R_WRONG_SIGNATURE_LENGTH);
- return 0;
- }
-
- if (hash_nid == NID_md5_sha1 && msg_len != SSL_SIG_LENGTH) {
- OPENSSL_PUT_ERROR(RSA, RSA_R_INVALID_MESSAGE_LENGTH);
- return 0;
- }
-
- buf = OPENSSL_malloc(rsa_size);
- if (!buf) {
- OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
- return 0;
- }
-
- if (!RSA_verify_raw(rsa, &len, buf, rsa_size, sig, sig_len,
- RSA_PKCS1_PADDING)) {
- goto out;
- }
-
- if (!RSA_add_pkcs1_prefix(&signed_msg, &signed_msg_len,
- &signed_msg_is_alloced, hash_nid, msg, msg_len)) {
- goto out;
- }
-
- if (len != signed_msg_len || CRYPTO_memcmp(buf, signed_msg, len) != 0) {
- OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_SIGNATURE);
- goto out;
- }
-
- ret = 1;
-
- out:
- OPENSSL_free(buf);
- if (signed_msg_is_alloced) {
- OPENSSL_free(signed_msg);
- }
- return ret;
- }
-
- static void bn_free_and_null(BIGNUM **bn) {
- BN_free(*bn);
- *bn = NULL;
- }
-
- int RSA_check_key(const RSA *key) {
- BIGNUM n, pm1, qm1, lcm, gcd, de, dmp1, dmq1, iqmp;
- BN_CTX *ctx;
- int ok = 0, has_crt_values;
-
- if (RSA_is_opaque(key)) {
- /* Opaque keys can't be checked. */
- return 1;
- }
-
- if ((key->p != NULL) != (key->q != NULL)) {
- OPENSSL_PUT_ERROR(RSA, RSA_R_ONLY_ONE_OF_P_Q_GIVEN);
- return 0;
- }
-
- if (!key->n || !key->e) {
- OPENSSL_PUT_ERROR(RSA, RSA_R_VALUE_MISSING);
- return 0;
- }
-
- if (!key->d || !key->p) {
- /* For a public key, or without p and q, there's nothing that can be
- * checked. */
- return 1;
- }
-
- ctx = BN_CTX_new();
- if (ctx == NULL) {
- OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
- return 0;
- }
-
- BN_init(&n);
- BN_init(&pm1);
- BN_init(&qm1);
- BN_init(&lcm);
- BN_init(&gcd);
- BN_init(&de);
- BN_init(&dmp1);
- BN_init(&dmq1);
- BN_init(&iqmp);
-
- if (!BN_mul(&n, key->p, key->q, ctx) ||
- /* lcm = lcm(prime-1, for all primes) */
- !BN_sub(&pm1, key->p, BN_value_one()) ||
- !BN_sub(&qm1, key->q, BN_value_one()) ||
- !BN_mul(&lcm, &pm1, &qm1, ctx) ||
- !BN_gcd(&gcd, &pm1, &qm1, ctx)) {
- OPENSSL_PUT_ERROR(RSA, ERR_LIB_BN);
- goto out;
- }
-
- size_t num_additional_primes = 0;
- if (key->additional_primes != NULL) {
- num_additional_primes = sk_RSA_additional_prime_num(key->additional_primes);
- }
-
- size_t i;
- for (i = 0; i < num_additional_primes; i++) {
- const RSA_additional_prime *ap =
- sk_RSA_additional_prime_value(key->additional_primes, i);
- if (!BN_mul(&n, &n, ap->prime, ctx) ||
- !BN_sub(&pm1, ap->prime, BN_value_one()) ||
- !BN_mul(&lcm, &lcm, &pm1, ctx) ||
- !BN_gcd(&gcd, &gcd, &pm1, ctx)) {
- OPENSSL_PUT_ERROR(RSA, ERR_LIB_BN);
- goto out;
- }
- }
-
- if (!BN_div(&lcm, NULL, &lcm, &gcd, ctx) ||
- !BN_gcd(&gcd, &pm1, &qm1, ctx) ||
- /* de = d*e mod lcm(prime-1, for all primes). */
- !BN_mod_mul(&de, key->d, key->e, &lcm, ctx)) {
- OPENSSL_PUT_ERROR(RSA, ERR_LIB_BN);
- goto out;
- }
-
- if (BN_cmp(&n, key->n) != 0) {
- OPENSSL_PUT_ERROR(RSA, RSA_R_N_NOT_EQUAL_P_Q);
- goto out;
- }
-
- if (!BN_is_one(&de)) {
- OPENSSL_PUT_ERROR(RSA, RSA_R_D_E_NOT_CONGRUENT_TO_1);
- goto out;
- }
-
- has_crt_values = key->dmp1 != NULL;
- if (has_crt_values != (key->dmq1 != NULL) ||
- has_crt_values != (key->iqmp != NULL)) {
- OPENSSL_PUT_ERROR(RSA, RSA_R_INCONSISTENT_SET_OF_CRT_VALUES);
- goto out;
- }
-
- if (has_crt_values && num_additional_primes == 0) {
- if (/* dmp1 = d mod (p-1) */
- !BN_mod(&dmp1, key->d, &pm1, ctx) ||
- /* dmq1 = d mod (q-1) */
- !BN_mod(&dmq1, key->d, &qm1, ctx) ||
- /* iqmp = q^-1 mod p */
- !BN_mod_inverse(&iqmp, key->q, key->p, ctx)) {
- OPENSSL_PUT_ERROR(RSA, ERR_LIB_BN);
- goto out;
- }
-
- if (BN_cmp(&dmp1, key->dmp1) != 0 ||
- BN_cmp(&dmq1, key->dmq1) != 0 ||
- BN_cmp(&iqmp, key->iqmp) != 0) {
- OPENSSL_PUT_ERROR(RSA, RSA_R_CRT_VALUES_INCORRECT);
- goto out;
- }
- }
-
- ok = 1;
-
- out:
- BN_free(&n);
- BN_free(&pm1);
- BN_free(&qm1);
- BN_free(&lcm);
- BN_free(&gcd);
- BN_free(&de);
- BN_free(&dmp1);
- BN_free(&dmq1);
- BN_free(&iqmp);
- BN_CTX_free(ctx);
-
- return ok;
- }
-
- int RSA_recover_crt_params(RSA *rsa) {
- BN_CTX *ctx;
- BIGNUM *totient, *rem, *multiple, *p_plus_q, *p_minus_q;
- int ok = 0;
-
- if (rsa->n == NULL || rsa->e == NULL || rsa->d == NULL) {
- OPENSSL_PUT_ERROR(RSA, RSA_R_EMPTY_PUBLIC_KEY);
- return 0;
- }
-
- if (rsa->p || rsa->q || rsa->dmp1 || rsa->dmq1 || rsa->iqmp) {
- OPENSSL_PUT_ERROR(RSA, RSA_R_CRT_PARAMS_ALREADY_GIVEN);
- return 0;
- }
-
- if (rsa->additional_primes != NULL) {
- OPENSSL_PUT_ERROR(RSA, RSA_R_CANNOT_RECOVER_MULTI_PRIME_KEY);
- return 0;
- }
-
- /* This uses the algorithm from section 9B of the RSA paper:
- * http://people.csail.mit.edu/rivest/Rsapaper.pdf */
-
- ctx = BN_CTX_new();
- if (ctx == NULL) {
- OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
- return 0;
- }
-
- BN_CTX_start(ctx);
- totient = BN_CTX_get(ctx);
- rem = BN_CTX_get(ctx);
- multiple = BN_CTX_get(ctx);
- p_plus_q = BN_CTX_get(ctx);
- p_minus_q = BN_CTX_get(ctx);
-
- if (totient == NULL || rem == NULL || multiple == NULL || p_plus_q == NULL ||
- p_minus_q == NULL) {
- OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
- goto err;
- }
-
- /* ed-1 is a small multiple of φ(n). */
- if (!BN_mul(totient, rsa->e, rsa->d, ctx) ||
- !BN_sub_word(totient, 1) ||
- /* φ(n) =
- * pq - p - q + 1 =
- * n - (p + q) + 1
- *
- * Thus n is a reasonable estimate for φ(n). So, (ed-1)/n will be very
- * close. But, when we calculate the quotient, we'll be truncating it
- * because we discard the remainder. Thus (ed-1)/multiple will be >= n,
- * which the totient cannot be. So we add one to the estimate.
- *
- * Consider ed-1 as:
- *
- * multiple * (n - (p+q) + 1) =
- * multiple*n - multiple*(p+q) + multiple
- *
- * When we divide by n, the first term becomes multiple and, since
- * multiple and p+q is tiny compared to n, the second and third terms can
- * be ignored. Thus I claim that subtracting one from the estimate is
- * sufficient. */
- !BN_div(multiple, NULL, totient, rsa->n, ctx) ||
- !BN_add_word(multiple, 1) ||
- !BN_div(totient, rem, totient, multiple, ctx)) {
- OPENSSL_PUT_ERROR(RSA, ERR_R_BN_LIB);
- goto err;
- }
-
- if (!BN_is_zero(rem)) {
- OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_RSA_PARAMETERS);
- goto err;
- }
-
- rsa->p = BN_new();
- rsa->q = BN_new();
- rsa->dmp1 = BN_new();
- rsa->dmq1 = BN_new();
- rsa->iqmp = BN_new();
- if (rsa->p == NULL || rsa->q == NULL || rsa->dmp1 == NULL || rsa->dmq1 ==
- NULL || rsa->iqmp == NULL) {
- OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
- goto err;
- }
-
- /* φ(n) = n - (p + q) + 1 =>
- * n - totient + 1 = p + q */
- if (!BN_sub(p_plus_q, rsa->n, totient) ||
- !BN_add_word(p_plus_q, 1) ||
- /* p - q = sqrt((p+q)^2 - 4n) */
- !BN_sqr(rem, p_plus_q, ctx) ||
- !BN_lshift(multiple, rsa->n, 2) ||
- !BN_sub(rem, rem, multiple) ||
- !BN_sqrt(p_minus_q, rem, ctx) ||
- /* q is 1/2 (p+q)-(p-q) */
- !BN_sub(rsa->q, p_plus_q, p_minus_q) ||
- !BN_rshift1(rsa->q, rsa->q) ||
- !BN_div(rsa->p, NULL, rsa->n, rsa->q, ctx) ||
- !BN_mul(multiple, rsa->p, rsa->q, ctx)) {
- OPENSSL_PUT_ERROR(RSA, ERR_R_BN_LIB);
- goto err;
- }
-
- if (BN_cmp(multiple, rsa->n) != 0) {
- OPENSSL_PUT_ERROR(RSA, RSA_R_INTERNAL_ERROR);
- goto err;
- }
-
- if (!BN_sub(rem, rsa->p, BN_value_one()) ||
- !BN_mod(rsa->dmp1, rsa->d, rem, ctx) ||
- !BN_sub(rem, rsa->q, BN_value_one()) ||
- !BN_mod(rsa->dmq1, rsa->d, rem, ctx) ||
- !BN_mod_inverse(rsa->iqmp, rsa->q, rsa->p, ctx)) {
- OPENSSL_PUT_ERROR(RSA, ERR_R_BN_LIB);
- goto err;
- }
-
- ok = 1;
-
- err:
- BN_CTX_end(ctx);
- BN_CTX_free(ctx);
- if (!ok) {
- bn_free_and_null(&rsa->p);
- bn_free_and_null(&rsa->q);
- bn_free_and_null(&rsa->dmp1);
- bn_free_and_null(&rsa->dmq1);
- bn_free_and_null(&rsa->iqmp);
- }
- return ok;
- }
-
- int RSA_private_transform(RSA *rsa, uint8_t *out, const uint8_t *in,
- size_t len) {
- if (rsa->meth->private_transform) {
- return rsa->meth->private_transform(rsa, out, in, len);
- }
-
- return RSA_default_method.private_transform(rsa, out, in, len);
- }
-
- int RSA_blinding_on(RSA *rsa, BN_CTX *ctx) {
- return 1;
- }
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